Some computer systems require a reliable supply of electrical power. For example, a server used to process sales and accounting transactions may be considered to be a critical to a corporation, and may thus require a continuous supply of electrical power. In such computer systems, electrical power may be provided by multiple power supply units (PSUs). In particular, one (or more) of the PSUs may be held in reserve, to be brought on line in the case of a failure of an active PSU.
Weighing against the performance required of a power supply system is a need to reduce energy consumption. PSUs in a power supply system, if not managed properly, may consume high amounts of energy. Government standards have been enacted to encourage a reduction in the use of power supply systems, both in an effort to conserve resources and to help reduce the energy costs of companies using power supply systems. Further, companies that design power supply systems and their components, including control systems, may be motivated to exceed the government standards that have been created.